Simple inexpensive method of measuring the temporal spreading of a light pulse propagating in a turbid medium

A simple and inexpensive method of measuring statistical parameters related to the time lengthening arising in the propagation of a light pulse in a turbid medium is presented. The method is based on the repetition of attenuation measurements of a light beam passing through the turbid medium when the absorption coefficient of the medium surrounding the diffusing particles is varied. The measurements are carried out using a cw source and a simple optical receiver with a common photodiode as a detector. The results of two measurements are reported together with the results of numerical simulations carried out using the scattering properties and geometric parameters corresponding to the experimental situation. Numerical results were obtained using a Monte Carlo based method. Good agreement between experimental and numerical results was found.